diff --git a/.github/workflows/preview.yml b/.github/workflows/preview.yml
index 4bea6ea5f..2dcc70700 100644
--- a/.github/workflows/preview.yml
+++ b/.github/workflows/preview.yml
@@ -1,6 +1,6 @@
 name: 🔂 Surge PR Preview
 
-on: [push, pull_request_target]
+on: pull_request_target
 
 jobs:
   preview:
@@ -9,6 +9,8 @@ jobs:
       PUBLIC_PATH: '/'
     steps:
       - uses: actions/checkout@v2
+        with:
+          ref: refs/pull/${{ github.event.pull_request.number }}/merge
       - uses: afc163/surge-preview@v1
         with:
           surge_token: ${{ secrets.SURGE_TOKEN }}
diff --git a/src/nav-bar/index.less b/src/nav-bar/index.less
index 8f72ac913..1fed3ee1f 100644
--- a/src/nav-bar/index.less
+++ b/src/nav-bar/index.less
@@ -15,8 +15,8 @@
   }
 
   &--safe-area-inset-top {
-    padding-top: constant(safe-area-inset-bottom);
-    padding-top: env(safe-area-inset-bottom);
+    padding-top: constant(safe-area-inset-top);
+    padding-top: env(safe-area-inset-top);
   }
 
   .van-icon {